Lunyu XV. 1. (392)

Confucius refuses to talk on military affairs. [...]
1. The duke Ling of Wei asked Confucius about tactics. Confucius replied, "I have heard all about sacrificial vessels, but I have not learned military matters." On this, he took his departure the next day. [...]

Legge XV.1.

Duke Ling of Wei asked Confucius about military formations. Confucius answered, 'I have, indeed, heard something about the use of sacrificial vessels, but I have never studied the matter of com- manding troops.' The next day he departed.